APATITE-TYPE LANTHANUM SILICATE POLYCRYSTAL AND METHOD FOR MANUFACTURING THE SAME, OXIDE ION CONDUCTOR, AND SOLID ELECTROLYTE

摘要

PROBLEM TO BE SOLVED: To provide an apatite-type lanthanum silicate polycrystal whose crystal axes are unidirectionally oriented and having a high ion conductivity and to provide a manufacturing method capable of obtaining such an apatite-type lanthanum silicate polycrystal without recourse to complicated processes.SOLUTION: The provided apatite-type lanthanum silicate polycrystal is obtained by removing all layers but the layer positioned as the very median member from a laminate structure of an "unreacted first layer/apatite-type lanthanum silicate polycrystal layer/unreacted third layer" constitution generated as a result of the heating, at a temperature yielding element diffusions, of a joined body obtained by laminating a first layer including LaSiOas a main component, a second layer including LaSiOas a main component, and a third layer including LaSiOas a main component in the order of "first layer/second layer/third layer"; a method for manufacturing the apatite-type lanthanum silicate polycrystal is also provided.